






//****************************************************************for 循环
@for $i from 1 to 5{
    .a#{$i}{
        background: url(../img/#{$i}.jpg) no-repeat center orange;
    }
} 

//*****************************************************************while 循环
$j:1;
@while $j<5{
    .b#{$j}{
        background: url(../img/#{$j}.jpg) no-repeat center #ccc;
    }
    $j:$j +1
}
 
//*****************************************************************each 循环
@each $k in 1,2,3,4{
    .c#{$k}{
        background: url(../img/#{$k}.jpg) no-repeat center green;
    }
}

 
.aaa{
    width: 200px;
    height: 200px;
    display: inline-block;
    background-size: contain;
}

